Washington ? True art would never be mistaken for a crude, paint-by-the-numbers copy. But a researcher has developed a statistical tool for determining whether a purported masterpiece is only a skilled imitation, suggesting that art may be a numbers game after all.

Using high-resolution digital images and complex mathematical formulas, associate professor Hany Farid of Dartmouth College analyzed works by Renaissance artists to determine their authenticity.

His computer program was able to accurately separate eight drawings by 16th century Flemish artist Pieter Bruegel the Elder from five drawings by imitators. It also found that portions of a painting by Italian artist Pietro di Cristoforo Vannucci, known as Perugino, were probably done by Perugino’s apprentices.

Farid presented his work in Monday’s Proceedings of the National Academy of Sciences.

Farid, a professor of applied mathematics and computer science, said his computer program was similar to digital analysis of other visual media like photographs, in which digital compression converts the photograph or image to an accessible, lower-resolution format like JPEG.

In this case, high-resolution photographs of the painting and drawings were digitally compressed so the art image could be broken down into simpler, varying elements.

With the Perugino painting “Madonna with Child” — which depicts the madonna, baby Jesus and two saints on either side of the pair — characteristics like the distance between faces and the orientation of horizontal, vertical and diagonal elements were subjected to statistical analysis based in part from what was known about the style of the Italian master.

Farid’s analysis found that Perugino painted only a portion of the work and his apprentices other parts — a common practice among Renaissance masters whose work was in such high demand that they kept workshops of painters to carry out their many commissions.

A researcher has developed a statistical tool for determining whether a purported masterpiece is only a skilled imitation. With the 1505 Perugino painting Madonna